The key is to take time off earlier. I spent october doing the odd collegiate mtb race (low-key) and riding whenever I felt like it. Hiking, climbing, just hangin out while it was still warm. Now, it's a bit chilly but I have the motivation to START my next season right, and start it now. If I was racing cross or still racing anything I would be burned right now, like you, and would not want to do anything until January (like last year...)

Too many people race for too long. If you're going to race cross, take at least a week or two super easy and low key in August. It's a mental game with yourself.